Rapid deconvolution of low-resolution time-of-flight data using Bayesian inference.

The deconvolution of low-resolution time-of-flight data has numerous advantages, including the ability to extract additional information from the experimental data. We augment the well-known Lucy-Richardson deconvolution algorithm using various Bayesian prior distributions and show that a prior of second-differences of the signal outperforms the standard Lucy-Richardson algorithm, accelerating the rate of convergence by more than a factor of four, while preserving the peak amplitude ratios of a similar fraction of the total peaks. A novel stopping criterion and boosting mechanism are implemented to ensure that these methods converge to a similar final entropy and local minima are avoided.

Rapid mixing of colliding picoliter liquid droplets delivered through-space from piezoelectric-actuated pipettes characterized by time-resolved fluorescence monitoring.

Rapid mixing of aqueous solutions is a crucial first step to study the kinetics of fast biochemical reactions with high temporal resolution. Remarkable progress toward this goal has been made through the development of advanced stopped-flow mixing techniques resulting in reduced dead times, and thereby extending reaction monitoring capabilities to numerous biochemical systems. Concurrently, piezoelectric actuators for through-space liquid droplet sample delivery have also been applied in several experimental systems, providing discrete picoliter sample volume delivery and precision sample deposition onto a surface, free of confinement within microfluidic devices, tubing, or other physical constraints.

Sampling of Tissues with Laser Ablation for Proteomics: Comparison of Picosecond Infrared Laser and Microsecond Infrared Laser.

It was recently shown that sampling of tissues with a picosecond infrared laser (PIRL) for analysis with bottom-up proteomics is advantageous compared to mechanical homogenization. Because the cold ablation of tissues with PIRL irradiation is soft, proteins remain intact and even enzymatic activities are detectable in PIRL homogenates. In contrast, it was observed that irradiation of tissues with a microsecond infrared laser (MIRL) heats the tissue, thereby causing significant damage.

Soft Picosecond Infrared Laser Extraction of Highly Charged Proteins and Peptides from Bulk Liquid Water for Mass Spectrometry.

We report the soft laser extraction and production of highly charged peptide and protein ions for mass spectrometry directly from bulk liquid water at atmospheric pressure and room temperature, using picosecond infrared laser ablation. Stable ion signal from singly charged small molecules, as well as highly charged biomolecular ions, from aqueous solutions at low laser pulse fluence (∼0.3 J cm) is demonstrated.

Comparative study of wound healing in rat skin following incision with a novel picosecond infrared laser (PIRL) and different surgical modalities.

Background And Objective: As a result of wound healing the original tissue is replaced by dysfunctional scar tissue. Reduced tissue damage during surgical procedures beneficially affects the size of the resulting scar and overall healing time. Thus the choice of a particular surgical instrument can have a significant influence on the postoperative wound healing.

Protein species as diagnostic markers.

Unlabelled: Many diseases are associated with protein species perturbations. A prominent example of an established diagnostic marker is the glycated protein species of hemoglobin, termed HbA1c. HbA1c concentration is increased in the blood of diabetes mellitus patients due to their poor control of blood glucose levels resulting in an increased non-enzymatic glycosylation of hemoglobin producing HbA1c.

Note: A simple image processing based fiducial auto-alignment method for sample registration.

A simple method for the location and auto-alignment of sample fiducials for sample registration using widely available MATLAB/LabVIEW software is demonstrated. The method is robust, easily implemented, and applicable to a wide variety of experiment types for improved reproducibility and increased setup speed. The software uses image processing to locate and measure the diameter and center point of circular fiducials for distance self-calibration and iterative alignment and can be used with most imaging systems.

Ultrafast extraction of proteins from tissues using desorption by impulsive vibrational excitation.

A picosecond IR laser (PIRL) can be used to blast proteins out of tissues through desorption by impulsive excitation (DIVE) of intramolecular vibrational states of water molecules in the cell in less than a millisecond. With PIRL-DIVE proteins covering a range of a few kDa up to several MDa are extracted in high quantities compared to conventional approaches. The chemical composition of extracted proteins remains unaltered and even enzymatic activities are maintained.

Cobinamide production of hydrogen in a homogeneous aqueous photochemical system, and assembly and photoreduction in a (βα)8 protein.

Components of a protein-integrated, earth-abundant metal macrocycle catalyst, with the purpose of H2 production from aqueous protons under green conditions, are characterized. The cobalt-corrin complex, cobinamide, is demonstrated to produce H2 (4.4 ± 1.

Characterization of protein contributions to cobalt-carbon bond cleavage catalysis in adenosylcobalamin-dependent ethanolamine ammonia-lyase by using photolysis in the ternary complex.

Protein contributions to the substrate-triggered cleavage of the cobalt-carbon (Co-C) bond and formation of the cob(II)alamin-5'-deoxyadenosyl radical pair in the adenosylcobalamin (AdoCbl)-dependent ethanolamine ammonia-lyase (EAL) from Salmonella typhimurium have been studied by using pulsed-laser photolysis of AdoCbl in the EAL-AdoCbl-substrate ternary complex, and time-resolved probing of the photoproduct dynamics by using ultraviolet-visible absorption spectroscopy on the 10(-7)-10(-1) s time scale. Experiments were performed in a fluid dimethylsulfoxide/water cryosolvent system at 240 K, under conditions of kinetic competence for thermal cleavage of the Co-C bond in the ternary complex. The static ultraviolet-visible absorption spectra of holo-EAL and ternary complex are comparable, indicating that the binding of substrate does not labilize the cofactor cobalt-carbon (Co-C) bond by significantly distorting the equilibrium AdoCbl structure.

Photolysis of adenosylcobalamin and radical pair recombination in ethanolamine ammonia-lyase probed on the micro- to millisecond time scale by using time-resolved optical absorption spectroscopy.

The quantum yield and kinetics of decay of cob(II)alamin formed by pulsed-laser photolysis of adenosylcobalamin (AdoCbl; coenzyme B(12)) in AdoCbl-dependent ethanolamine ammonia-lyase (EAL) from Salmonella typhimurium have been studied on the 10(-7)-10(-1) s time scale at 295 K by using transient ultraviolet-visible absorption spectroscopy. The aim is to probe the mechanism of formation and stabilization of the cob(II)alamin-5'-deoxyadenosyl radical pair, which is a key intermediate in EAL catalysis, and the influence of substrate binding on this process. Substrate binding is required for cobalt-carbon bond cleavage in the native system.

Electron ionization time-of-flight mass spectrometry: historical review and current applications.

This review presents an overview of electron ionization time-of-flight mass spectroscopy (EITOFMS), beginning with its early development to the employment of modern high-resolution electron ionization sources. The EITOFMS is demonstrated to be ideally suited for analytical and basic chemical physics studies. Studies of the formation of positive ions by electron ionization time-of-flight mass spectroscopy have been responsible for many of the known ionization potentials of molecules and radicals, as well as accepted bond dissociation energies for ions and neutral molecules.